text: Carbon is a primary component of all known life on Earth, and represents approximately 45–50% of all dry biomass. Carbon compounds occur naturally in great abundance on Earth. Complex biological molecules consist of carbon atoms bonded with other elements, especially oxygen and hydrogen and frequently also nitrogen, phosphorus, and sulfur (collectively known as CHNOPS).
  Because it is lightweight and relatively small in size, carbon molecules are easy for enzymes to manipulate. Carbonic anhydrase is part of this process. Carbon has an atomic number of 6 on the periodic table.  The carbon cycle is a biogeochemical cycle that is important in maintaining life on Earth over a long time span. The cycle includes carbon sequestration and carbon sinks. Plate tectonics are needed for life over a long time span, and carbon-based life is important in the plate tectonics process. An abundance of iron and sulfur based Anoxygenic photosynthesis life forms that lived from 3.80 to 3.85 billion years ago on Earth produces an abundance black shale deposits. These shale deposits increases heat flow and crust buoyancy, especially on the sea floor, this help increase plate tectonics. Talc is an other organic mineral, that helps drive Plate tectonics. Inorganic processes also help drive plate tectonics. Carbon-based photosynthesis life caused a rise in oxygen on  Earth, this increase of oxygen help plate tectonics to form the first continents. It is frequently assumed in astrobiology that if life exists elsewhere in the Universe, it will also be carbon-based. Critics, like Carl Sagan in 1973, refer to this assumption as carbon chauvinism.